//
//  EAGLView.m
//  MSAATest
//
//  Created by Feng Ye on 10-8-5.
//  Copyright __MyCompanyName__ 2010. All rights reserved.
//

#import "EAGLView.h"

#import "ES1Renderer.h"

@interface EAGLView()
- (void) initOES;
@end

@implementation EAGLView

@synthesize animating;
@synthesize renderer;
@dynamic animationFrameInterval;

// You must implement this method
+ (Class)layerClass{
    return [CAEAGLLayer class];
}

//The EAGL view is stored in the nib file. When it's unarchived it's sent -initWithCoder:
- (id)initWithCoder:(NSCoder*)coder{    
    if ((self = [super initWithCoder:coder])){
        [self initOES];
    }

    return self;
}

- (id) initWithFrame:(CGRect)frame{
    if (self = [super initWithFrame:frame]) {
        [self initOES];
    }
    return self;
}

// 初始化OpenGL ES 开发环境
- (void) initOES{
    // Get the layer
    CAEAGLLayer *eaglLayer = (CAEAGLLayer *)self.layer;
    
    eaglLayer.opaque = TRUE;
    eaglLayer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys:
                                    [NSNumber numberWithBool:FALSE], kEAGLDrawablePropertyRetainedBacking, kEAGLColorFormatRGBA8, kEAGLDrawablePropertyColorFormat, nil];
    
    // 此处采用OpenGL ES1
    renderer = [[ES1Renderer alloc] init];
    
    animating = FALSE;
    displayLinkSupported = FALSE;
    animationFrameInterval = 3;
    displayLink = nil;
    animationTimer = nil;
    
    // A system version of 3.1 or greater is required to use CADisplayLink. The NSTimer
    // class is used as fallback when it isn't available.
    NSString *reqSysVer = @"3.1";
    NSString *currSysVer = [[UIDevice currentDevice] systemVersion];
    if ([currSysVer compare:reqSysVer options:NSNumericSearch] != NSOrderedAscending)
        displayLinkSupported = TRUE;
}

- (void)drawView:(id)sender{
    [renderer render];
}

- (void)layoutSubviews{
    [renderer resizeFromLayer:(CAEAGLLayer*)self.layer];
    [self drawView:nil];
}

- (NSInteger)animationFrameInterval{
    return animationFrameInterval;
}

- (void)setAnimationFrameInterval:(NSInteger)frameInterval{
    // Frame interval defines how many display frames must pass between each time the
    // display link fires. The display link will only fire 30 times a second when the
    // frame internal is two on a display that refreshes 60 times a second. The default
    // frame interval setting of one will fire 60 times a second when the display refreshes
    // at 60 times a second. A frame interval setting of less than one results in undefined
    // behavior.
    if (frameInterval >= 1){
        animationFrameInterval = frameInterval;

        if (animating){
            [self stopAnimation];
            [self startAnimation];
        }
    }
}

- (void)startAnimation{
    if (!animating){
        if (displayLinkSupported){
            // CADisplayLink is API new to iPhone SDK 3.1. Compiling against earlier versions will result in a warning, but can be dismissed
            // if the system version runtime check for CADisplayLink exists in -initWithCoder:. The runtime check ensures this code will
            // not be called in system versions earlier than 3.1.

            displayLink = [NSClassFromString(@"CADisplayLink") displayLinkWithTarget:self selector:@selector(drawView:)];
            [displayLink setFrameInterval:animationFrameInterval];
            [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
        }
        else{
            animationTimer = [NSTimer scheduledTimerWithTimeInterval:(NSTimeInterval)((1.0 / 60.0) * animationFrameInterval) target:self selector:@selector(drawView:) userInfo:nil repeats:TRUE];
        }
        animating = TRUE;
    }
}

- (void)stopAnimation{
    if (animating){
        if (displayLinkSupported){
            [displayLink invalidate];
            displayLink = nil;
        }
        else{
            [animationTimer invalidate];
            animationTimer = nil;
        }

        animating = FALSE;
    }
}

- (void)dealloc{
    [self stopAnimation];
    
    [renderer release];

    [super dealloc];
}

@end
